1. Field Of The Invention
This invention is related to the field of conveyor housing access ports and closures therefor as used with conveyor belt cleaning apparatus.
2. Description Of The Prior Art
Conveyor belt cleaners heretofore have required inspection windows, or doors, at openings provided to enable access to be had to an interior operation, or mechanism, for the purpose of viewing such interior after which the closure is immediately restored to its original sealed condition. These prior closures invariably involved a rigid door which may have been mounted for hinged movement away from the inspection opening, or mounted for sliding movement away from the opening but always in the form of an inflexible panel covering the access opening.
A number of prior art patents disclose various types of closure panels mounted in cooperative relationship to variously contoured inspection openings.
For instance, Cottrell U.S. Pat. No. 1,204,949 discloses a removable cover plate as used with milling machinery and is secured by bolts, or the like, to cover an access opening to a grain receiving boot.
Sturtevant U.S. Pat. No. 1,366,103 relates to an elevator for fertilizer and discloses a full length removable wall, or door, which provides for access to an elevator section for maintenance of the section interior. The removable panels are rigid and secured by a multiplicity of fastenings.
Rahlson U.S. Pat. No. 2,618,375 relates to elevating machinery and utilizes a curved cover member that is hinged for opening movement to expose the interior.
Johnston U.S. Pat. No. 3,376,669 illustrates a bucket type elevator mechanism utilizing an access door that is hinged and which is secured by a pair of locking bars.
Schnell et al. U.S. Pat. No. 3,470,994 is directed to a clean-out opening as used in a fertilizer hopper and discloses a curved cover member that is held in place by a releasable latching arrangement.
U.S. Pat. No. 4,170,293 to Campbell for an Enclosed Conveyor discloses the use of a number of curved access doors hingedly mounted on the conveyor and which of necessity are of rigid construction.
Prior Martin Engineering Company Pat. Nos. 4,098,394 and 4,249,650 both show hingedly mounted doors over an inspection opening affording access to the interior of a conveyor housing.